1. Field
One or more embodiments described herein relate to a positive active material for a rechargeable lithium battery, a method for preparing a positive active material for a rechargeable lithium battery, and a rechargeable lithium battery including a positive active material for a rechargeable lithium battery.
2. Description of the Related Art
Rechargeable lithium batteries power many types of electronic devices, systems, and vehicles. These batteries use an organic electrolyte solution and thus may have greater discharge voltage and energy density than batteries that use an alkali aqueous solution.
A rechargeable lithium battery may be manufactured by an injecting an electrolyte solution into a battery cell. A negative electrode of the battery cell may include a negative active material capable of intercalating/deintercalating lithium. A positive electrode of the battery cell may include a positive active material capable of intercalating/deintercalating lithium. The positive active material for the positive electrode may include lithium-transition element composite oxides for intercalating lithium. Examples include LiCoO2, LiMn2O4, LiNiO2, LiNi1-xCoxO2(0<x<1), LiMnO2.
One type of rechargeable lithium battery uses a lithium nickel-based oxide. The content of nickel (Ni) is sufficiently large to improve energy density, despite low discharge voltage and volumetric density. When the lithium nickel-based oxide is used as a positive active material, a large amount of lithium may remain on the surface of the positive active material. This causes a deterioration in cycle characteristics, and also lowers stability and impedes long term use.